function roundFractional(x,n){
    return Math.round(x * Math.pow(10, n)) / Math.pow(10, n);
}

var myChart = echarts.init(document.getElementById('main'));

let xDate=[],
    yDate=[];

for(let i = 0;i <= 1;i+=0.1){
  xDate.push(roundFractional(i,1));
  yDate.push(h(i));
}

function h(p){
  return -1*p*Math.log2(p)-(1-p)*Math.log2(1-p);
}

  // 指定图表的配置项和数据
  var option = {
    title: {
      text: '二进熵函数曲线'
    },
    tooltip: {},
    legend: {
    data:['H(x)']
  },
  xAxis: {
    data: xDate
  },
  yAxis: {},
  series: [{
    name: '销量',
    type: 'line',
    smooth:true,
    data: yDate //H(p)
  }]
};

// 使用刚指定的配置项和数据显示图表。
myChart.setOption(option);
